HomeMy WebLinkAboutCDP 2020-0018; FORESTER RESIDENCE; GEOTECHNICAL ADDENDUM AND RESPONSES TO THIRD PARTY GEOTECHNICAL REVIEW; 2022-09-06 ADVANCED GEOTECHNICAL SOLUTIONS, INC. 485 Corporate Drive, Suite B Escondido, California 92029 Telephone: (619) 867-0487 Fax: (714) 786-5661
ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 867-0487 (619) 867-0487
John Forester September 6, 2022
300 Carlsbad Village Drive, Suite 108a-335 P/W 1901-03 Carlsbad, California 92008 Report No. 1901-03-B-5 Attention: Mr. John Forester Subject: Geotechnical Addendum and Response to Third-Party Geotechnical Review, Proposed Single-Family Residence, 4464 Adams Street, Carlsbad, California Gentlepersons: In accordance with your request, Advanced Geotechnical Solutions, Inc. (AGS) has prepared this response
to third party geotechnical review comments issued by the City of Carlsbad regarding the geotechnical
investigation report and addendum prepared by AGS (2020, 2021) for the proposed single-family residence
project to be located on 4464 Adams Street. The review comments are presented below followed by our
responses. A copy of the review comment sheet is attached in Appendix B.
Comment 1: Due to the age of the geotechnical investigation, the Consultant should update the project
seismic, grading and foundation recommendations to comply with requirements of the 2019 California
Building Code and ASCE 7-16. (repeat comment-as only seismic design parameters were address in the
"Geotechnical Addendum and Response to Third-Party Geotechnical. Review...'', please discuss if any
updates to the grading and foundation recommendations are necessary based on the geotechnical update.).
AGS Response: As noted, AGS provided updated seismic design parameters for the project based
on 2019 California Building Code and ASCE 7-16. Based on our review of the geotechnical
investigation report and addendum by AGS (2020, 2022), no additional seismic, grading and
foundation recommendations are necessary to comply with requirements of the 2019 California
Building Code and ASCE 7-16.
Comment 2: The Consultant should address the gross and surficial stability of proposed slopes (repeat
comment - please provide the plots of the direct shear tests for the onsite soils that is discussed in the
consultant's response to this comment, and please also provide the complete data print-outs of the slope
stability analysis (static and pseudo-static) that is presented in the Geotechnical Addendum and Response
to Third-Party geotechnical Review.
AGS Response: The plots of the direct shear tests performed on samples recovered at the project
site were presented in Appendix C - Laboratory Test Results of referenced project geotechnical
report by AGS (2020). A copy of the direct shear plots from the referenced report is presented in
Appendix C and summary of the direct shear test results is presented in Table 1, below:
TABLE 1 - DIRECT SHEAR TEST RESULTS
Boring and Sample Depth Description (USCS) DS Test Moist Unit Weight (pcf) Friction Angle - Peak (degrees) Cohesion - Peak (psf)
B-1 @ 8.5-9 ft. Qop (SM) Undisturbed 125.2 39 198
B-2 @ 0-3 ft. Afu (SM) Remolded to 90% 129.5 31 288
B-2 @ 10-10.5 ft. Qop (SM) Undisturbed 118.1 32 252
Based on the direct shear test results and our engineering judgement, the following shear strength
~GS
September 6, 2022 Page 2 P/W 1901-03 Report No. 1901-03-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
parameters presented in our previous response to review comments (AGS, 2021) were selected for
our slope stability analyses:
TABLE 2 - SHEAR STRENGTH PARAMETERS
Material Friction Angle (degrees) Cohesion (psf) Moist Density (pcf)
Compacted Fill – afc 30 200 130
Old Paralic Deposits – Qop 32 200 125
The complete data printout of the slope stability analyses (static and pseudo-static) are presented
in Appendix D.
Comment 3: The Consultant should address the impacts to adjacent property and improvements as a result
of site grading and construction (repeat comment - as the Consultant's response to this comment in the
'Geotechnical Addendum and Response to Third-Party Geotechnical Review... '' indicates off-site grading
into Adams Street ROW and the adjacent vacant lot may be necessary for construction of the fill key at the
southern portion of the site, please provide alternative recommendations for the grading if permission is not
granted by the city and/or adjacent neighbor.).
AGS Response: Based on AGS’ review, site grading and construction will not impact the adjacent
properties or improvements. If permission for offsite grading into Adams Street right-of-way
and the adjacent vacant lot to the east is not granted, temporary shoring along Adams Street
right-of-way and the adjacent vacant lot to the east may be used to complete the grading and
keyway construction on the southern limits of the project.
Comment 4: The Consultant should provide recommendations for fill keys, benching and subdrainage
(widths, depths, etc.). (repeat comment - please provide the composition of the backdrain (size, and type of
pipe, amount and size of gravel, filter fabric, etc.) for the fill key.)
AGS Response: Fill slopes on the project are designed at 2:1 ratio (horizontal to vertical) or flatter.
Fill slopes, when properly constructed with onsite materials, are expected to be grossly stable as
designed. Fill slopes will be subject to surficial erosion and should be landscaped as quickly as
possible.
Keyways should be constructed at the toe of all fill slopes “toeing” on existing or cut grade. Fill
keys should have a minimum width equal to one-half the height of ascending slope, and not less
than 15 feet. Unsuitable soil removals below the toe of proposed fill slopes should extend from the
catch point of the design toe outward at a minimum 1:1 projection into approved material to
establish the location of the key. Backcuts to establish that removal geometry should be cut no
steeper than 1:1 or as recommended by the Geotechnical Consultant.
Additional fill key and backdrain construction recommendations are provided in the details below:
September 6, 2022 Page 3 P/W 1901-03 Report No. 1901-03-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Detail 1 - Fill Key Recommendations
Detail 2 - Backdrain Recommendations
CODE COMPLIANT
BLANKET FILL -AS REQUIRED BY
GEOTECHNICAL CONSULTANT
AND/OR CODE COMPLIANCE
(3 FOOT MIN.)
SETBACK, 15 FOOT MIN.~
0~o<c-
~0~ o<c-S "
-_-_-_---_-_-_-_-_-_-_-_-_-_-_-_-~-~~~---_-_-_-_-_-_-_-_-_-_-_-_[£! ""''
CONSTRUCT DRAIN OUTLET BENCH WIDTH
A MINIMUM 1-FOOT VARIES
ABOVE GRADE
~. __ - - - - - - - - - --- --~-
0
~---_-_-_-_-_-_-_-_-_-_(£1 !:~g~ ~~~GHT ····-~
CODE COMPLIANT KEYWAY
WITH MINIMUM DIMENSIONS:
TOE 2 FOOT MIN.
HEEL 3 FOOT MIN.
WIDTH 15 FOOT MIN.
DRAIN 2-FT. MIN
~~;iRIAL ~I<_. : ·.· .. -.~II
FILTER FABRIC >,_> _.'.._i·_-:<· 2-FT.
: ; = I:o <·-MIN
4-INCH SOLID 2-INCH MIN
OUTLET PIPE BELOW PIPE
OPTION 1
SEE DETAIL 2 FOR DRAIN SPECIFICATIONS
NOTES:
1. DRAIN OUTLETS TO BE PROVIDED EVERY 100 FEET
CONNECT TO PERFORATED DRAIN PIPE BY "L" OR "T"
AT A MINIMUM 2% GRADIENT.
2. THE NECESSITY AND LOCATION OF ADDITIONAL
DRAINS SHALL BE DETERMINED IN THE FIELD
BY THE GEOTECHNICAL CONSULTANT. UPPER STAGE
OUTLETS SHOULD BE EMPTIED ONTO CONCRETE
TERRACE DRAINS.
3. DRAIN PIPE TO EXTEND FULL LENGTH OF
STABILIZATION/BUTTRESS WITH A MINIMUM GRADIENT
OF 2% TO SOLID OUTLET PIPES.
4. LOCATION OF DRAINS AND OUTLETS
SHOULD BE DOCUMENTED BY PROJECT
CIVIL ENGINEER. OUTLETS MUST BE KEPT
UNOBSTRUCTED AT ALL TIMES.
DRAIN 2-FT. MIN.
~~;iRIAL ~IE .·."· .-:-:)II
FILTER FABRIC \·0: >> 7: : hb< i-iti·
4-INCH SOLID 2-INCH MIN.
OUTLET PIPE BELOW PIPE
OPTION 2
DRAIN MATERIAL: GRAVEL TRENCH TO BE FILLED WITH 314-INCH MAX ROCK OR APPROVED EQUIVALENT
SUBSTITUTE
FILTER FABRIC: MIRAFI 140 FILTER FABRIC OR EQUIVALENT SUBSTITUTE WITH A MINIMUM 6-INCH OVERLAP
PIPE: 4-INCH ABS OR PVC PIPE OR APPROVED EQUIVALENT SUBSTITUTE WITH A MINIMUM
OF 8 PERFORATIONS (114-INCH DIAMETER) PER LINEAL FOOT IN
BOTTOM HALF OF PIPE
(ASTM D2751, SDR-35 OR ASTM D3034, SDR-35
ASTM D1527, SCHD. 40 OR ASTM D1785, SCHD. 40)
September 6, 2022 Page 4 P/W 1901-03 Report No. 1901-03-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
Comment 5: The consultant should provide a list of recommended testing and observation during grading
and construction. (repeat comment),
AGS Response: Recommendations for testing and observation during grading and construction
remedial grading were provided by AGS (2020) in Section 8.2 - Observation During Construction
of the geotechnical report. Additional recommendations are provided in Appendix E - Earthwork
Specifications and Grading Details - Section VIII Geotechnical Observation and Testing.
Conditions of the referenced reports remain applicable unless specifically superseded herein.
Advanced Geotechnical Solutions, Inc., appreciates the opportunity to provide you with geotechnical
consulting services and professional opinions. If you have any questions, please contact the undersigned
at (619) 867-0487.
Respectfully Submitted, Advanced Geotechnical Solutions, Inc.
___________________________________
ANDRES BERNAL, Sr. Geotechnical Engineer RCE 62366/GE 2715, Reg. Exp. 9-30-23
_______________________________
PAUL J. DERISI, President CEG 2536, Reg. Exp. 5-31-23
Distribution: (1) Addressee
Attachments: Appendix A - References Appendix B - Geotechnical Review Comments Appendix C - Direct Shear Test Plots Appendix D - Slope Stability Analyses (Static and Pseudo-Static) Appendix E - Earthwork Specifications and Grading Details
September 6, 2022 Page 5 P/W 1901-03 Report No. 1901-03-B-5
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX A
REFERENCES
Advanced Geotechnical Solutions, 2020, Geotechnical Investigation and Preliminary Design
Recommendations for Proposed Single-Family Residence, 4464 Adams Street, Carlsbad, California,
dated December 31, 2019, Report No. 1901-03-B-2.
---, 2021, Geotechnical Addendum and Response to Third-Party Geotechnical Review, Proposed Single-
Family Residence, 4464 Adams Street, Carlsbad, California, dated December 17, 2021, Report No.
1901-03-B-3.
City of Carlsbad, 2022, Geotechnical Report Review, Forester Residence, 4464 Adams Street, Carlsbad,
California (2nd review), Project ID: CDP2020-0018, GR2022-0031 dated August 2, 2022.
Fusion Eng Tech, 2022, Grading and Improvement Plans for Forester Residence, 4464 Adams Street, Sheet
4 of 10, plot dated April 22, 2022.
Hetherington Engineering, 2021, Third-Party Geotechnical Review Comments (First) 4464 Adams Street,
Carlsbad, California, GR2021-0037/CDP2021-0037, their Project No. 9541.1, Log No. 21675, dated
November 11, 2021.
GEOTECHNICAL REPORT REVIEW
DA TE: August 2, 2022
TO: City of Carlsbad Land Development Engineering 1635 Faraday Avenue Carlsbad, CA 92008
Attention: Nichole Fine
PROJECT ID: CDP2020-0018
GRADING PERMIT NO.: GR2021-0037
SUBJECT: Forester Residence, 4464 Adams Street, Carlsbad, California (2nd review)
-Items Submitted by Applicant Items Being Returned to Aoolicant •"Geotechnical Addendum and Response to Third-•Written report review comments.Party Geotechnical Review, Proposed Single-Family Residence, 4464 Adams Street, Carlsbad,California,• by Advanced Geotechnical Solutions,Inc., dated December 17. 2021.--•"Third-Party Geotechnical Review (First), 4464 •
Adams Street, Carlsbad, California," byHetherington Engineering, Inc., dated November11, 2021.
Based on our review of the submitted geotechnical report, we are providing the following comments that should be addressed prior to the next submittal. Please provide complete and
thorough written responses to all comments. Please note that the basis for this review consists solely of the review of the "Geotechnical Addendum and Response to Third-Party Geotechnical
Review ... ," by AGS, Inc. and "Third-Party Geotechnical Review (First), 4464 Adams Street...," by Hetherington Engineering, Inc. reference above.
GEOTECHNICAL COMMENTS:
1.Due to the age of the geotechnical investigation, the Consultant should update the project
seismic, grading and foundation recommendations to comply with requirements of the
2019 California Building Code and ASCE 7-16. (repeat comment-as only seismic design
parameters were address in the "Geotechnical Addendum and Response to Third-Party
APPENDIX B
GR2022-0031 August 2, 2022 Page 2 of 3
Geotechn1cal. Review ... '', please discuss if a.ny updates .to the grading and foundation recommendations are necessary based on the geotechnical update.)
2 The Consultant should address the gross and surficia'I stabil1ity o.f proposed s,lopes (repeat comment -please pro·vide the plots of the direct shea.r tests for the on-•site s,oils that is discussed in the consultant's response to this comme.nt, a1nd please also provide the complete data prinf .. outs of the slope stability analysis (static a.n'd pseuda·-static) that is p.resented in the 11Geotechn1ical .Addendu:m and Response to Th"rd-P.arty Geotech.nicalReview ... ''.)
3.The Consultant shou.ld ad·dress the impacts t•o adjacent property a1nd ·1mprovements as aresult of site grading and construction. (repeat comment -as the Consultant's responseto this comment in the Geotechnica1I Ad,den.dum and Response to Third-PartyGeotechn.ical Review .. .'1 indicates off-site grading into Adams· Street ROW and theadjacent vacant lot may be necessary for con.structio.n of the fill key at the sauthe,rn portionof the site, please provide alternative recommendations far the grading if pe,rmission is no,tgranted by the city and/or adjacent neighbor.)
4.The Consultant should pr,ovide recomjmendations for fill keys, benching and subdrainage(widths, depths, et.). (repeat comment-please pro·vide the composition of the backdra,in(siz.e ,and type of pipe, amount and size of gravel, filter fabric, etc.) for the fill ker,�)
5.The Co'nsultant should provide a list of recommended testing and obs·ervation d1uringgrading and co,nstru'ction. (repeat comment),
•
•
-r.
Project Name: 4464 Adams St Excavation: B-2
Location: Carlsbad Depth: 0-3 ft
Project No.: 1901-03 Tested by: FV
Date:Reviewed by:
Samples Tested 123 Soil Type: Dark Brn SC-SM
Intial Moisture (%) 9.5 9.5 9.5 Test: Remolded 90%
Initial Dry Density (pcf) 118.3 118.3 118.3 Method: Drained
Normal Stress (psf) 1000 2000 4000 Consolidation: Yes
Peak Shear Stress (psf) 912 1452 2700 Saturation: Yes
Ult. Shear Stress (psf) 696 1332 2472 Shear Rate (in/min):0.01
Strength Parameters Peak Ultimate
Friction Angle, phi (deg)31 30
Cohesion (psf)288 126
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR - ASTM D3080
1/21/2020
‐0.02
‐0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.00 0.10 0.20 0.30
Ve
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(i
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)
Displacement (in)
Vertical Deformation v. Displacement
4000
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0.00 0.10 0.20 0.30
Sh
e
a
r
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Shear Stress v. Displacement
4000
2000
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0
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0 500 1000 1500 2000 2500 3000 3500 4000 4500
Sh
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(p
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)
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Peak
Peak
Ultimate
Ultimate
FIGURE C-1
APPENDIX C
-
1-I I 7 -
~
I_ I I I _J c====----t-t-1
.... ····· ..
--------
Project Name: 4464 Adams ST Excavation: B-1
Location: Carlsbad Depth: 8.5-9.0 ft
Project No.: 1901-03 Tested by: FV
Date:Reviewed by:
Samples Tested 123 Soil Type: Qop
Intial Moisture (%) 6.1 6.1 6.1 Test: Undisturbed
Initial Dry Density (pcf) 116.6 118.0 122.5 Method: Drained
Normal Stress (psf) 1000 2000 4000 Consolidation: Yes
Peak Shear Stress (psf) 1080 1692 3456 Saturation: Yes
Ult. Shear Stress (psf) 744 1416 3084 Shear Rate (in/min):0.01
Strength Parameters Peak Ultimate
Friction Angle, phi (deg)39 36
Cohesion (psf)198 0
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR - ASTM D3080
1/7/2020
‐0.02
‐0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.00 0.10 0.20 0.30
Ve
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Vertical Deformation v. Displacement
4000
2000
10000
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3500
4000
0.00 0.10 0.20 0.30
Sh
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(p
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Displacement (in)
Shear Stress v. Displacement
4000
2000
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0
500
1000
1500
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3500
4000
4500
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Sh
e
a
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r
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s
s
(p
s
f
)
Normal Stress (psf)
Peak
Peak
Ultimate
Ultimate
FIGURE C-2
••••• ••••••••••• ····••o,,, ················
------
------j,1/ ----7
;r 1-----I
Project Name: 4464 Adams St Excavation: B-2
Location: Carlsbad Depth: 10-10.5 ft
Project No.: 1901-03 Tested by: FV
Date:Reviewed by:
Samples Tested 123 Soil Type: Qop
Intial Moisture (%) 3.8 3.8 3.8 Test: Undisturbed
Initial Dry Density (pcf) 110.7 113.8 110.0 Method: Drained
Normal Stress (psf) 1000 2000 4000 Consolidation: Yes
Peak Shear Stress (psf) 840 1548 2724 Saturation: Yes
Ult. Shear Stress (psf) 672 1272 2484 Shear Rate (in/min):0.01
Strength Parameters Peak Ultimate
Friction Angle, phi (deg)32 31
Cohesion (psf)252 66
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
DIRECT SHEAR - ASTM D3080
1/21/2020
‐0.02
‐0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.00 0.10 0.20 0.30
Ve
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i
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Vertical Deformation v. Displacement
4000
2000
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500
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0.00 0.10 0.20 0.30
Sh
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Shear Stress v. Displacement
4000
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0 500 1000 1500 2000 2500 3000 3500 4000 4500
Sh
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)
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Peak
Peak
Ultimate
Ultimate
FIGURE C-3
··········· ··············
' f ,, ' , ! ,
--... -... __ _.,,,,,.v--.,.----------
/'---~------------------------------------------
II J
K:\1901-03 Forester Residence\Slope Stability\highest fill - static.OUT Page 1
*** GSTABL7 ***
** GSTABL7 by Garry H. Gregory, P.E. **
** Original Version 1.0, January 1996; Current Version 2.005, Sept. 2006 **
(All Rights Reserved-Unauthorized Use Prohibited)
*********************************************************************************
SLOPE STABILITY ANALYSIS SYSTEM
Modified Bishop, Simplified Janbu, or GLE Method of Slices.
(Includes Spencer & Morgenstern-Price Type Analysis)
Including Pier/Pile, Reinforcement, Soil Nail, Tieback,
Nonlinear Undrained Shear Strength, Curved Phi Envelope,
Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water
Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces.
*********************************************************************************
Analysis Run Date: 12/17/2021
Time of Run:04:55PM
Run By:AGS
Input Data Filename: K:\1901-03 Forester Residence\Slope Stability\highest fill -
static.in
Output Filename:K:\1901-03 Forester Residence\Slope Stability\highest fill -
static.OUT
Unit System:English
Plotted Output Filename: K:\1901-03 Forester Residence\Slope Stability\highest fill -
static.PLT
PROBLEM DESCRIPTION: 1901-03 Forester Residence 2:1 Fill
Slope (Static)
BOUNDARY COORDINATES
4 Top Boundaries
7 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. (ft) (ft) (ft) (ft) Below Bnd
1 0.00 66.00 20.00 66.00 2
2 20.00 66.00 48.00 80.00 1
3 48.00 80.00 52.00 80.00 1
4 52.00 80.00 100.00 80.00 2
5 20.00 66.00 20.10 64.00 2
6 20.10 64.00 35.00 63.00 2
7 35.00 63.00 52.00 80.00 2
User Specified Y-Origin = 40.00(ft)
Default X-Plus Value = 0.00(ft)
Default Y-Plus Value = 0.00(ft)
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) (pcf) (psf) (deg) Param. (psf) No.
1 130.0 130.0 200.0 30.0 0.00 0.0 0
2 125.0 125.0 200.0 32.0 0.00 0.0 0
Specified Peak Ground Acceleration Coefficient (A) = 0.528(g)
Specified Horizontal Earthquake Coefficient (kh) = 0.150(g)
Specified Vertical Earthquake Coefficient (kv) = 0.000(g)
Specified Seismic Pore-Pressure Factor = 0.000
EARTHQUAKE DATA HAS BEEN SUPPRESSED
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
4000 Trial Surfaces Have Been Generated.
4000 Surface(s) Initiate(s) From Each Of 1 Points Equally Spaced
Along The Ground Surface Between X = 20.00(ft)
and X = 20.00(ft)
Each Surface Terminates Between X = 24.00(ft)
and X = 100.00(ft)
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y = 0.00(ft)
3.00(ft) Line Segments Define Each Trial Failure Surface.
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Evaluated. They Are
Ordered - Most Critical First.
* * Safety Factors Are Calculated By The Modified Bishop Method * *
Total Number of Trial Surfaces Attempted = 4000
Number of Trial Surfaces With Valid FS = 4000
Statistical Data On All Valid FS Values:
APPENDIX D
K:\1901-03 Forester Residence\Slope Stability\highest fill - static.OUT Page 2
FS Max = 25.451 FS Min = 2.469 FS Ave = 5.327
Standard Deviation = 2.652 Coefficient of Variation = 49.78 %
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 2.469 ***
Individual data on the 13 slices
Water Water Tie Tie Earthquake
Force Force Force Force Force Surcharge
Slice Width Weight Top Bot Norm Tan Hor Ver Load
No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs)
1 3.0 355.5 0.0 0.0 0. 0. 0.0 0.0 0.0
2 3.0 1017.4 0.0 0.0 0. 0. 0.0 0.0 0.0
3 3.0 1556.5 0.0 0.0 0. 0. 0.0 0.0 0.0
4 2.9 1952.6 0.0 0.0 0. 0. 0.0 0.0 0.0
5 2.9 2194.4 0.0 0.0 0. 0. 0.0 0.0 0.0
6 2.8 2279.5 0.0 0.0 0. 0. 0.0 0.0 0.0
7 2.7 2214.6 0.0 0.0 0. 0. 0.0 0.0 0.0
8 2.5 2015.5 0.0 0.0 0. 0. 0.0 0.0 0.0
9 2.3 1705.8 0.0 0.0 0. 0. 0.0 0.0 0.0
10 2.1 1316.1 0.0 0.0 0. 0. 0.0 0.0 0.0
11 0.8 400.9 0.0 0.0 0. 0. 0.0 0.0 0.0
12 1.1 439.9 0.0 0.0 0. 0. 0.0 0.0 0.0
13 1.6 232.3 0.0 0.0 0. 0. 0.0 0.0 0.0
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 2.469 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
K:\1901-03 Forester Residence\Slope Stability\highest fill - static.OUT Page 3
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 2.469 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.983 65.681
3 25.983 65.655
4 28.971 65.923
5 31.918 66.483
6 34.796 67.329
7 37.578 68.452
8 40.236 69.843
9 42.745 71.488
10 45.081 73.370
11 47.222 75.472
12 49.146 77.774
13 50.663 80.000
Circle Center At X = 24.744 ; Y = 96.219 ; and Radius = 30.589
Factor of Safety
*** 2.472 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.983 65.681
3 25.983 65.655
4 28.971 65.923
5 31.918 66.483
6 34.796 67.329
7 37.578 68.452
8 40.236 69.843
9 42.745 71.488
10 45.081 73.370
11 47.222 75.472
12 49.146 77.774
13 50.663 80.000
Circle Center At X = 24.744 ; Y = 96.219 ; and Radius = 30.589
Factor of Safety
*** 2.472 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.954 65.476
3 25.948 65.290
4 28.944 65.444
5 31.904 65.936
6 34.788 66.760
7 37.561 67.905
8 40.186 69.357
9 42.631 71.097
10 44.862 73.101
11 46.853 75.346
12 48.576 77.802
13 49.773 80.000
Circle Center At X = 26.090 ; Y = 91.752 ; and Radius = 26.462
Factor of Safety
*** 2.485 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.954 65.476
3 25.948 65.290
K:\1901-03 Forester Residence\Slope Stability\highest fill - static.OUT Page 4
4 28.944 65.444
5 31.904 65.936
6 34.788 66.760
7 37.561 67.905
8 40.186 69.357
9 42.631 71.097
10 44.862 73.101
11 46.853 75.346
12 48.576 77.802
13 49.773 80.000
Circle Center At X = 26.090 ; Y = 91.752 ; and Radius = 26.462
Factor of Safety
*** 2.485 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.960 65.509
3 25.954 65.330
4 28.951 65.466
5 31.918 65.914
6 34.821 66.669
7 37.629 67.724
8 40.312 69.067
9 42.840 70.683
10 45.184 72.554
11 47.321 74.660
12 49.225 76.978
13 50.877 79.482
14 51.145 80.000
Circle Center At X = 26.168 ; Y = 93.922 ; and Radius = 28.595
Factor of Safety
*** 2.487 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.960 65.509
3 25.954 65.330
4 28.951 65.466
5 31.918 65.914
6 34.821 66.669
7 37.629 67.724
8 40.312 69.067
9 42.840 70.683
10 45.184 72.554
11 47.321 74.660
12 49.225 76.978
13 50.877 79.482
14 51.145 80.000
Circle Center At X = 26.168 ; Y = 93.922 ; and Radius = 28.595
Factor of Safety
*** 2.487 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.960 65.509
3 25.954 65.330
4 28.951 65.466
5 31.918 65.914
6 34.821 66.669
7 37.629 67.724
8 40.312 69.067
9 42.840 70.683
10 45.184 72.554
11 47.321 74.660
12 49.225 76.978
13 50.877 79.482
14 51.145 80.000
K:\1901-03 Forester Residence\Slope Stability\highest fill - static.OUT Page 5
Circle Center At X = 26.168 ; Y = 93.922 ; and Radius = 28.595
Factor of Safety
*** 2.487 ***
**** END OF GSTABL7 OUTPUT ****
K:\1901-03 Forester Residence\Slope Stability\highest fill - pseudo static.OUT Page 1
*** GSTABL7 ***
** GSTABL7 by Garry H. Gregory, P.E. **
** Original Version 1.0, January 1996; Current Version 2.005, Sept. 2006 **
(All Rights Reserved-Unauthorized Use Prohibited)
*********************************************************************************
SLOPE STABILITY ANALYSIS SYSTEM
Modified Bishop, Simplified Janbu, or GLE Method of Slices.
(Includes Spencer & Morgenstern-Price Type Analysis)
Including Pier/Pile, Reinforcement, Soil Nail, Tieback,
Nonlinear Undrained Shear Strength, Curved Phi Envelope,
Anisotropic Soil, Fiber-Reinforced Soil, Boundary Loads, Water
Surfaces, Pseudo-Static & Newmark Earthquake, and Applied Forces.
*********************************************************************************
Analysis Run Date: 12/17/2021
Time of Run:04:54PM
Run By:AGS
Input Data Filename: K:\1901-03 Forester Residence\Slope Stability\highest fill -
pseudo static.in
Output Filename:K:\1901-03 Forester Residence\Slope Stability\highest fill -
pseudo static.OUT
Unit System:English
Plotted Output Filename: K:\1901-03 Forester Residence\Slope Stability\highest fill -
pseudo static.PLT
PROBLEM DESCRIPTION: 1901-03 Forester Residence 2:1 Fill
Slope (Pseudo-static)
BOUNDARY COORDINATES
4 Top Boundaries
7 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. (ft) (ft) (ft) (ft) Below Bnd
1 0.00 66.00 20.00 66.00 2
2 20.00 66.00 48.00 80.00 1
3 48.00 80.00 52.00 80.00 1
4 52.00 80.00 100.00 80.00 2
5 20.00 66.00 20.10 64.00 2
6 20.10 64.00 35.00 63.00 2
7 35.00 63.00 52.00 80.00 2
User Specified Y-Origin = 40.00(ft)
Default X-Plus Value = 0.00(ft)
Default Y-Plus Value = 0.00(ft)
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) (pcf) (psf) (deg) Param. (psf) No.
1 130.0 130.0 200.0 30.0 0.00 0.0 0
2 125.0 125.0 200.0 32.0 0.00 0.0 0
Specified Peak Ground Acceleration Coefficient (A) = 0.528(g)
Specified Horizontal Earthquake Coefficient (kh) = 0.150(g)
Specified Vertical Earthquake Coefficient (kv) = 0.000(g)
Specified Seismic Pore-Pressure Factor = 0.000
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
4000 Trial Surfaces Have Been Generated.
4000 Surface(s) Initiate(s) From Each Of 1 Points Equally Spaced
Along The Ground Surface Between X = 20.00(ft)
and X = 20.00(ft)
Each Surface Terminates Between X = 24.00(ft)
and X = 100.00(ft)
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y = 0.00(ft)
3.00(ft) Line Segments Define Each Trial Failure Surface.
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Evaluated. They Are
Ordered - Most Critical First.
* * Safety Factors Are Calculated By The Modified Bishop Method * *
Total Number of Trial Surfaces Attempted = 4000
Number of Trial Surfaces With Valid FS = 4000
Statistical Data On All Valid FS Values:
FS Max = 19.440 FS Min = 1.823 FS Ave = 3.468
K:\1901-03 Forester Residence\Slope Stability\highest fill - pseudo static.OUT Page 2
Standard Deviation = 1.979 Coefficient of Variation = 57.07 %
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.977 65.628
3 25.975 65.534
4 28.970 65.720
5 31.934 66.184
6 34.842 66.921
7 37.669 67.925
8 40.390 69.188
9 42.982 70.698
10 45.422 72.443
11 47.689 74.408
12 49.764 76.575
13 51.629 78.925
14 52.329 80.000
Circle Center At X = 25.491 ; Y = 97.647 ; and Radius = 32.120
Factor of Safety
*** 1.823 ***
Individual data on the 16 slices
Water Water Tie Tie Earthquake
Force Force Force Force Force Surcharge
Slice Width Weight Top Bot Norm Tan Hor Ver Load
No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs)
1 3.0 360.0 0.0 0.0 0. 0. 54.0 0.0 0.0
2 3.0 1035.7 0.0 0.0 0. 0. 155.3 0.0 0.0
3 3.0 1599.4 0.0 0.0 0. 0. 239.9 0.0 0.0
4 3.0 2032.1 0.0 0.0 0. 0. 304.8 0.0 0.0
5 2.9 2321.8 0.0 0.0 0. 0. 348.3 0.0 0.0
6 2.8 2464.0 0.0 0.0 0. 0. 369.6 0.0 0.0
7 2.7 2461.5 0.0 0.0 0. 0. 369.2 0.0 0.0
8 1.9 1722.7 0.0 0.0 0. 0. 258.4 0.0 0.0
9 0.7 601.8 0.0 0.0 0. 0. 90.3 0.0 0.0
10 2.4 2063.9 0.0 0.0 0. 0. 309.6 0.0 0.0
11 2.3 1712.2 0.0 0.0 0. 0. 256.8 0.0 0.0
12 0.3 214.1 0.0 0.0 0. 0. 32.1 0.0 0.0
13 1.8 986.1 0.0 0.0 0. 0. 147.9 0.0 0.0
14 1.9 536.6 0.0 0.0 0. 0. 80.5 0.0 0.0
15 0.4 37.0 0.0 0.0 0. 0. 5.6 0.0 0.0
16 0.3 10.4 0.0 0.0 0. 0. 1.6 0.0 0.0
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.977 65.628
3 25.975 65.534
4 28.970 65.720
5 31.934 66.184
6 34.842 66.921
7 37.669 67.925
8 40.390 69.188
9 42.982 70.698
10 45.422 72.443
11 47.689 74.408
12 49.764 76.575
13 51.629 78.925
14 52.329 80.000
Circle Center At X = 25.491 ; Y = 97.647 ; and Radius = 32.120
Factor of Safety
*** 1.823 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
K:\1901-03 Forester Residence\Slope Stability\highest fill - pseudo static.OUT Page 3
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 1.825 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 1.825 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.980 65.655
3 25.980 65.607
4 28.969 65.857
5 31.919 66.403
6 34.800 67.239
7 37.584 68.357
8 40.244 69.745
9 42.752 71.391
10 45.085 73.277
11 47.219 75.386
12 49.133 77.696
13 50.684 80.000
Circle Center At X = 24.959 ; Y = 95.778 ; and Radius = 30.188
Factor of Safety
*** 1.825 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.983 65.681
3 25.983 65.655
4 28.971 65.923
5 31.918 66.483
6 34.796 67.329
7 37.578 68.452
8 40.236 69.843
9 42.745 71.488
10 45.081 73.370
11 47.222 75.472
12 49.146 77.774
13 50.663 80.000
Circle Center At X = 24.744 ; Y = 96.219 ; and Radius = 30.589
Factor of Safety
*** 1.827 ***
Failure Surface Specified By 13 Coordinate Points
Point X-Surf Y-Surf
K:\1901-03 Forester Residence\Slope Stability\highest fill - pseudo static.OUT Page 4
No. (ft) (ft)
1 20.000 66.000
2 22.983 65.681
3 25.983 65.655
4 28.971 65.923
5 31.918 66.483
6 34.796 67.329
7 37.578 68.452
8 40.236 69.843
9 42.745 71.488
10 45.081 73.370
11 47.222 75.472
12 49.146 77.774
13 50.663 80.000
Circle Center At X = 24.744 ; Y = 96.219 ; and Radius = 30.589
Factor of Safety
*** 1.827 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.990 65.751
3 25.990 65.748
4 28.980 65.990
5 31.940 66.475
6 34.851 67.202
7 37.693 68.164
8 40.446 69.355
9 43.093 70.767
10 45.615 72.391
11 47.996 74.216
12 50.220 76.230
13 52.271 78.419
14 53.527 80.000
Circle Center At X = 24.544 ; Y = 102.262 ; and Radius = 36.546
Factor of Safety
*** 1.828 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.990 65.751
3 25.990 65.748
4 28.980 65.990
5 31.940 66.475
6 34.851 67.202
7 37.693 68.164
8 40.446 69.355
9 43.093 70.767
10 45.615 72.391
11 47.996 74.216
12 50.220 76.230
13 52.271 78.419
14 53.527 80.000
Circle Center At X = 24.544 ; Y = 102.262 ; and Radius = 36.546
Factor of Safety
*** 1.828 ***
Failure Surface Specified By 14 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.000 66.000
2 22.960 65.509
3 25.954 65.330
4 28.951 65.466
5 31.918 65.914
6 34.821 66.669
7 37.629 67.724
8 40.312 69.067
9 42.840 70.683
10 45.184 72.554
K:\1901-03 Forester Residence\Slope Stability\highest fill - pseudo static.OUT Page 5
11 47.321 74.660
12 49.225 76.978
13 50.877 79.482
14 51.145 80.000
Circle Center At X = 26.168 ; Y = 93.922 ; and Radius = 28.595
Factor of Safety
*** 1.832 ***
**** END OF GSTABL7 OUTPUT ****
Page 1
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
APPENDIX E GENERAL EARTHWORK SPECIFICATIONS AND GRADING GUIDELINES
I. General
A. General procedures and requirements for earthwork and grading are presented herein. The earthwork and grading
recommendations provided in the geotechnical report are considered part of these specifications, and where the general
specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the
geotechnical report shall govern. Recommendations provided herein and in the geotechnical report may need to be
modified depending on the conditions encountered during grading.
B. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans,
specifications, applicable building codes, and local governing agency requirements. Where these requirements conflict,
the stricter requirements shall govern.
C. It is the contractor’s responsibility to read and understand the guidelines presented herein and in the geotechnical
report as well as the project plans and specifications. Information presented in the geotechnical report is subject to
verification during grading. The information presented on the exploration logs depict conditions at the particular time
of excavation and at the location of the excavation. Subsurface conditions present at other locations may differ, and the
passage of time may result in different subsurface conditions being encountered at the locations of the exploratory
excavations. The contractor shall perform an independent investigation and evaluate the nature of the surface and
subsurface conditions to be encountered and the procedures and equipment to be used in performing his work.
D. The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the
earthwork in accordance with applicable requirements. When the quality of work is less than that required, the
Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions
are corrected.
E. Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading procedures
and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines
presented herein. All remedial removals, clean-outs, removal bottoms, keyways, and subdrain installations should be
observed and documented by the Geotechnical Consultant prior to placing fill. It is the contractor’s responsibility to
appraise the Geotechnical Consultant of their schedules and notify the Geotechnical Consultant when those areas are
ready for observation.
F. The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading
and conduct tests.
II. Site Preparation
A.Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as required
by the Geotechnical Consultant, and such materials shall be properly disposed of offsite in a method acceptable to the
owner and governing agencies. Where applicable, the contractor may obtain permission from the Geotechnical
Consultant, owner, and governing agencies to dispose of vegetation and other deleterious materials in designated areas
onsite.
B. Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as
necessary to the satisfaction of the Geotechnical Consultant.
C. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, other
utilities, or other structures located within the limits of grading shall be removed and/or abandoned in accordance with
the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant.
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be scarified to a depth
of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform moisture content that is at or
near optimum moisture content. The scarified materials shall then be compacted to the project requirements and tested
as specified.
E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill.
A licensed surveyor shall provide survey control for determining elevations of processed areas and keyways.
III. Placement of Fill
A. Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that the
materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free
of organic matter and other deleterious materials, and be of a gradation, expansion potential, and/or strength that is
acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical
Consultant, and import materials shall be tested and approved prior to being imported.
B. Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials and
prevent abrupt changes in material type. Fill materials derived from benching should be dispersed throughout the fill
area instead of placing the materials within only an equipment-width from the cut/fill contact.
C. Oversize Materials: Rocks greater than 8 inches in largest dimension shall be disposed of offsite or be placed in
accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for
oversize rock placement. Rocks that are smaller than 8 inches in largest dimension may be utilized in the fill provided
that they are not nested and are their quantity and distribution are acceptable to the Geotechnical Consultant.
D. The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6 inches.
Each layer shall be spread evenly and shall be thoroughly mixed to obtain a near uniform moisture content and uniform
blend of materials.
E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as recommended by
the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water shall be
added, and the fill materials shall be blended so that a near uniform moisture content is achieved. If the moisture content
is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by discing, blading, or
other methods until the moisture content is acceptable.
F. Each layer of fill shall be compacted to the project standards in accordance to the project specifications and
recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical Consultant, the fill
shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM Test Method:
D1557-09.
G. Benching: Where placing fill on a slope exceeding a ratio of 5 to 1 (horizontal to vertical), the ground should be
keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable materials such
as firm materials or sound bedrock or as recommended by the Geotechnical Consultant. The minimum keyway width
shall be 15 feet and extend into suitable materials, or as recommended by the geotechnical report and approved by the
Geotechnical Consultant. The minimum keyway width for fill over cut slopes is also 15 feet, or as recommended by
the geotechnical report and approved by the Geotechnical Consultant. As a general rule, unless otherwise recommended
by the Geotechnical Consultant, the minimum width of the keyway shall be equal to 1/2 the height of the fill slope.
H. Slope Face: The specified minimum relative compaction shall be maintained out to the finish face of fill and
stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the compacted
core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may be achieved by
backrolling the slope face with suitable equipment or other methods that produce the designated result. Loose soil
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
should not be allowed to build up on the slope face. If present, loose soils shall be trimmed to expose the compacted
slope face.
I. Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and governing agencies, permanent fill
slopes shall be designed and constructed no steeper than 2 to 1 (horizontal to vertical).
J. Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated by the
Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation is
needed.
K. Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When grading is
interrupted by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture and
density of the previously placed compacted fill.
IV. Cut Slopes
A. The Geotechnical Consultant shall inspect all cut slopes, including fill over cut slopes, and shall be notified by the
contractor when cut slopes are started.
B. If adverse or potentially adverse conditions are encountered during grading, the Geotechnical Consultant shall
investigate, evaluate, and make recommendations to mitigate the adverse conditions.
C. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the
requirements of the local governing agencies. Short-term stability of the cut slopes and other excavations is the
contractor's responsibility.
V. Drainage
A. Backdrains and Subdrains: Backdrains and subdrains shall be provided in fill as recommended by the Geotechnical
Consultant and shall be constructed in accordance with the governing agency and/or recommendations of the
Geotechnical Consultant. The location of subdrains, especially outlets, shall be surveyed and recorded by the Civil
Engineer.
B. Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage shall not be
permitted to flow over the tops of slopes.
C. Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in accordance
with the recommendations of the Geotechnical Consultant.
D. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the prevailing
drainage.
VI. Erosion Control
A. All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the project
specifications and/or landscape architect's recommendations. Such measures to protect the slope face shall be
undertaken as soon as practical after completion of grading.
B. During construction, the contractor shall maintain proper drainage and prevent the ponding of water. The contractor
shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control
measures have been installed.
VII. Trench Excavation and Backfill
A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavations. Knowing and following
these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of 5 feet in depth
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
shall be shored or laid back. Trench excavations and open cuts exposing adverse geologic conditions may require further
evaluation by the Geotechnical Consultant. If a contractor fails to provide safe access for compaction testing, backfill
not tested due to safety concerns may be subject to removal.
B. Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where permitted
by the Geotechnical Consultant, the bedding materials can be densified by jetting.
C. Backfill: Jetting of backfill materials is generally not acceptable. Where permitted by the Geotechnical Consultant,
the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a
Sand Equivalent greater than 30.
VIII. Geotechnical Observation and Testing During Grading
A. Compaction Testing: Fill shall be tested by the Geotechnical Consultant for evaluation of general compliance with
the recommended compaction and moisture conditions. The tests shall be taken in the compacted soils beneath the
surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant by excavating
suitable test pits for testing of compacted fill.
B. Where tests indicate that the density of a layer of fill is less than required, or the moisture content not within
specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the fill. The
portions of the fill that are not within specifications shall be reworked until the required density and/or moisture content
has been attained. No additional fill shall be placed until the last lift of fill is tested and found to meet the project
specifications and approved by the Geotechnical Consultant.
C. If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock
or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill placement, results in a
quality of work that is unacceptable, the consultant shall notify the contractor, and the contractor shall rectify the
conditions, and if necessary, stop work until conditions are satisfactory.
D. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's
discretion. Generally, compaction tests shall be taken at intervals not exceeding two feet in fill height and 1,000 cubic
yards of fill materials placed.
E. Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal
coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient
grade stakes are established so that the Geotechnical Consultant can determine the test locations. Alternately, the test
locations can be surveyed and the results provided to the Geotechnical Consultant.
F. Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be removed and
recompacted at the contractor's expense. The depth and extent of removals will be determined by the Geotechnical
Consultant.
G. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the
Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with the approved
geotechnical report and project specifications.
H. Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit reports
documenting their observations during construction and test results. These reports may be subject to review by the local
governing agencies.